Among the state-of-the-art printed circuit board techniques, a flexible circuit board is the most promising one, which features light weight, small volume, dynamic flexibility, and resilient deformability and offers an important advantage of three-dimensional lay out in accordance with the volume and shape of the space for lay out. The flexible circuit board is of wide applications in consumer electronic products, such as digital cameras, mobile phones, and notebook computers, and has an un-neglected contribution to compactness and sophistication of the modern micro-electronic products in which the flexible printed circuit board plays an important role for transmission.
Recently, the flexible circuit board techniques have been applied to flat cables. A conventional flat cable comprises a plurality of conductors covered with insulation arranged to joint each other in a side-by-side fashion for forming a flat cable, which is commonly used for transmission of signal in a variety of electronic and communication equipments. The flexible circuit flat cables that are commonly used currently, according to the number of conductors needed in carrying out transmission, are constructed as different flexible circuit flat cables that are either a single-sided board, a double-sided board, or a multiple-layered board.
The conventional flat cables are only suitable for extending through an elongate space. However, the current electronic or communication devices often need to arrange a flexible circuit flat cable within a bore defined in a rotational axle. For example, in a commonly seen design of mobile phones or digital cameras, a cover or a screen is connected to a body of the phone or camera with a rotational axle. To allow signals to be transmitted from the body of the phone or the camera to the cover or the screen, the state-of-the-art techniques use small gauge wires or bundled extra thin leads to serve as a signal transmission line.